<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>Title</title>
    <style>
        div{
            width: 400px;
            margin: 100px auto;
        }
        a{
            display: block;
            width: 100px;
            height: 40px;
            margin-left:20px ;
            margin-top: 20px;
            background: #37A7D7;
            line-height: 40px;
            text-align: center;
            text-decoration: none;
        }
    </style>
</head>
<body>
<div>
    <a href="login.html">作业1</a>
    <a href="案例1.html">作业2</a>
    <a href="案例2.html">作业3</a>
    <a href="案例3.html">作业4</a>
    <a href="案例4.html">作业5</a>
    <a href="案例5.html">作业6</a>
    <a href="案例6.html">作业7</a>
</div>

</body>
</html>